Analgesics and antipyretics — formative SAQs

1. Paracetamol dose

Paracetamol is dosed at 15 mg per kg per dose, every four to six hours, to a maximum of 60 mg per kg per day. For this 16 kg child, one dose is 15 multiplied by 16, which is 240 mg per dose (rounded to an available formulation). The adult maximum is 1 g per dose and 4 g per day, and the calculation is capped there; this child's calculated daily maximum of 960 mg per day is below the 4 g adult ceiling, but the cap is checked explicitly. ^[2]

2. Ibuprofen dose

Ibuprofen is dosed at 5 to 10 mg per kg per dose, every six to eight hours, to a maximum of 30 mg per kg per day. For this 16 kg child, one dose is 80 to 160 mg (rounded sensibly). Ibuprofen is used from three months of age and over 5 kg, in a child who is drinking and passing urine and with no contraindication (dehydration, renal impairment, bleeding risk, aspirin-sensitive asthma). ^[2]

3. The alternating question

Routine alternating of paracetamol and ibuprofen is not recommended. The 2024 network meta-analysis found that short-term dual therapy can lower temperature modestly faster and for longer than either agent alone, but the effect is modest and dual therapy increases the risk of dosing error, parental confusion and doubled or exceeded doses. The defensible position is a single effective agent with a clear written plan first, reserving dual therapy for a distressed child who has not responded to monotherapy, with a written dosing schedule, the maximum daily dose stated, and a dosing syringe. Always ask what the child has already been given, because the commonest ceiling breach is a second preparation the carer did not realise contained paracetamol. ^{[1] [2]}

4. Safety restrictions and discharge safety-net

First, aspirin is avoided in children under 16 with viral illness because of the association with Reye syndrome; use paracetamol or ibuprofen. Second, codeine and tramadol are contraindicated in children under 12 and after tonsillectomy or adenoidectomy, because a CYP2D6 ultrarapid metaboliser converts the prodrug to a fatal morphine overdose; this child's mild pain does not require an opioid, but the restriction governs any escalation. The discharge safety-net names the features that should bring the child back urgently: reduced feeding, reduced wet nappies, lethargy or drowsiness, a fever that does not settle, a non-blanching rash, or difficulty breathing. ^{[6] [7]}